ABSTRACT:Ever since, inception of IT services on global level, lot of SDLC methodologies were developed to ensure proper balance between Time, Cost and Scope factors of the Projects. Over period of time, it was noticed that IT services using waterfall SDLC were gradually unable to deliver best requirements, despite having extensive experience in handling such large-scale IT projects. To overcome the shortcoming of the Waterfall SDLC model in early 2001, Agile SDLC methodology was introduced, which is even till today treated as de facto best industry standards of any IT projects across the globe as it successfully curtailed the demerits of earlier model such as dangers of traditional, front-end planning methods that often lead to downstream development pathologies. In this research paper, an attempt is made by the authors to understand how Agile SDLC methodology helps in improving efficacy of software development and various challenges faced during the development process. Limited research is done to highlight the efficacy of same across different variants of IT Projects. It is worthwhile to mentioned based on the past experiences of the authors that in case of Technology Migration IT Projects, bare implementation of Agile Methodology will not provide any addition advantage and success rate is extremely low. Authors has made an attempt to decipher the root causes which influences the efficacy of Agile SDLC methodology on Technology Migration Projects and suggest new SDLC methodology with list of KPIs to monitor the success rate of the project on real time basis.